PEARL HARBOR, Hawaii (AP) — The most recent commander of U.S. submarines in Asia and the Middle East took command on Wednesday of the entire Pacific Fleet submarine force.

Rear Adm. Phillip Sawyer succeeded Rear Adm. James Frank Caldwell Jr. during a ceremony on a platform atop the hull of the USS Jacksonville submarine.

Caldwell is leaving Hawaii for Washington to become the Navy’s inspector general.

Pacific Fleet commander Adm. Cecil Haney told the crowd of several hundred guests that he wasn’t able to properly salute Caldwell’s achievements because it would take a decade for everyone present to acquire the necessary security clearances to hear about his work.

“For over two-and-a-half years, Frank has worked brilliantly as a leader and has ensured our unique undersea capabilities remain the best in the world while ensuring the highest standards of operational excellence,” Haney said.

Haney said Caldwell improved readiness of the Pacific Fleet’s undersea surveillance and rescue capabilities. Caldwell also led the Pacific submarine force as it integrated newer Virginia-class submarines into the fleet, implemented a smoking ban and brought women to serve on board some submarines.

The Navy said Caldwell improved the way commanders communicate to help the submarine force better respond to threats. He also improved coordination among submarine warfare commanders.

Sawyer was most recently based in Yokosuka, Japan, as commander of Submarine Group 7, which operates in Asia and the Middle East. The 1983 Naval Academy graduate and career submarine officer previously commanded the USS La Jolla and Submarine Squadron 15 in Guam.

The U.S. Pacific Fleet’s submarine force is responsible for 60 percent of the Navy’s submarines. It’s also responsible for the nation’s ballistic missile submarine force in the Pacific.